Tendinopathy
The reason orthopedic surgeons stopped calling long-standing tennis elbow and Achilles pain “-itis” — it’s a failure to heal, not inflammation.
Why “tendinopathy” instead of “tendinitis”
For years, orthopedic surgeons used terms like “tennis elbow” or “Achilles tendinitis.” The “-itis” suffix means inflammation, and in the first few days after a new tendon injury, there is genuine inflammation. But in chronic cases — a patient who’s had tennis elbow for six months or longer — the tissue isn’t inflamed in the classical sense. Tendinopathy is the modern term because it describes what’s actually happening: a tendon that has failed to heal properly.
Under the microscope, a chronically symptomatic tendon shows collagen disorganization, abnormal ground substance, vascular invasion, and a stalled healing response. This is not the same as acute inflammation that you’d treat with ice and NSAIDs. The distinction matters enormously for treatment.
What causes the failure to heal
Tendinopathy usually develops from repetitive overuse. The tendon is loaded repeatedly but doesn’t get enough recovery time, or the loading pattern is poorly controlled. A desk worker with poor ergonomics and excessive wrist extension loads the lateral elbow (tennis elbow site) thousands of times weekly. A runner with calf muscle tightness and poor running mechanics puts chronic stress on the Achilles. Over weeks to months, the tendon accumulates micro-damage faster than repair can happen.
The tendon’s healing response gets stuck. It’s not that inflammation is absent; it’s that the inflammatory phase never properly transitions to the remodeling phase. Continued loading and continued re-injury prevent the repair cells from completing their work.
Why anti-inflammatories often don’t help
Because tendinopathy isn’t driven primarily by inflammation, NSAIDs and corticosteroids often don’t resolve it. They may numb the pain briefly, and a cortisone injection can sometimes provide short-term relief, but they don’t restart healing. Some evidence suggests that prolonged NSAID use may actually slow the remodeling of collagen, making the problem worse over time.
This is why we examine the tendon clinically and sometimes with ultrasound before jumping to treatment. If the tendon looks normal and the pain is truly inflammatory, NSAIDs are appropriate. If the imaging shows tendon thickening or disorganization, we pivot to treatments that actually stimulate healing.
Treatments that work
- Eccentric loading exercises. This is the foundation. Eccentric exercise means the tendon is loaded while lengthening — think of a slow, controlled lowering. This type of loading is uniquely effective at triggering tendon remodeling. A structured program of eccentric calf raises for Achilles tendinopathy or eccentric wrist extensions for tennis elbow takes weeks but produces real healing. Physical therapy guided by someone who understands tendinopathy is invaluable.
- Platelet-rich plasma (PRP). An injection of the patient’s own concentrated platelets, which release growth factors and stimulate tendon cell repair. Effective for moderate-to-severe tendinopathy, especially when paired with eccentric exercise.
- Tenex (percutaneous tenotomy). A minimally invasive procedure where a needle is used to selectively ablate damaged collagen, triggering a healing response. Often combined with ultrasound guidance to target degenerative zones precisely.
- Relative rest and load management. Continuing the activity that caused the problem won’t allow healing. Modifying the activity, changing ergonomics, or temporarily shifting to pain-free alternatives (like swimming instead of running) gives the tendon space to repair.
Common sites of tendinopathy
- Tennis elbow (lateral epicondylitis). The extensor tendon on the outside of the elbow. Common in racquet sports and repetitive gripping activities.
- Golfer’s elbow (medial epicondylitis). The flexor tendon on the inside of the elbow.
- Achilles tendinopathy. The tendon at the back of the heel. Runners and weekend athletes are at high risk.
- Patellar tendinopathy (jumper’s knee). The tendon below the kneecap. Basketball players and sprinters are particularly susceptible.
- Rotator cuff tendinopathy. One or more of the shoulder tendons, often from overhead repetition or poor scapular mechanics.
The timeline
Tendinopathy takes time to develop and time to heal. A new case of tennis elbow that’s only a few weeks old may respond quickly to rest and NSAIDs. But a patient who’s had the problem for years is dealing with chronically disorganized tissue that won’t bounce back in days. Eccentric exercise protocols typically take 6–12 weeks of consistent work. PRP or Tenex may require 4–8 weeks of post-procedure recovery before full benefit is felt. The payoff is genuine healing rather than temporary symptom suppression.